What was said in this video, I've often wondered. It seems that each age was getting worse. The Men were of a baser sort in each age (and also lived less long) than the Men of the previous ages. The Elves seemed to be less powerful in each age, as we can see Feanor and Galadriel having quite a bit of power but those like Thrandil and Legolas not seeming to have much, if any, magical power. The dwarves of the First Age had smithcraft enough to make a great gem to hold the Simaril, of which it was seemingly lost after the Battle of the Thousand Caves. The smithcraft of Moria was also lost after the Balrog sacked Durin's kingdom. And the smithcraft of Erebor was lost after Smaug attacked the Dale and the Lonely Mountain. Even evil seems to be weakening, as Sauron was quite weaker than Morgoth and was stronger in the Second Age than in the Third, and what evil comes after him in the Fourth Age would be weaker still. (Not necessarily less dangerous, but less mythical.) The only race that seems to be fading slowly is the Hobbit. They did seem to be getting lazier but it was stated that they knew how to make do with less in a pinch, and were able to fight back in the Battle of Bywater in the last round of the War of the Ring.